fe_dgq.h

Go to the documentation of this file.

// -----------------------------------------------------------------------------
//
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception OR LGPL-2.1-or-later
// Copyright (C) 2001 - 2026 by the deal.II authors
//
// This file is part of the deal.II library.
//
// Detailed license information governing the source code and contributions
// can be found in LICENSE.md and CONTRIBUTING.md at the top level directory.
//
// -----------------------------------------------------------------------------
 
#ifndef dealii_fe_dgq_h
#define dealii_fe_dgq_h
 
#include <deal.II/base/config.h>
 
#include <deal.II/base/mutex.h>
#include <deal.II/base/tensor_product_polynomials.h>
 
#include <deal.II/fe/fe_poly.h>
 
DEAL_II_NAMESPACE_OPEN
 
// Forward declarations
#ifndef DOXYGEN
template <int dim, int spacedim>
class MappingQ;
template <int dim>
class Quadrature;
#endif
 
template <int dim, int spacedim = dim>
class FE_DGQ : public FE_Poly<dim, spacedim>
{
public:
  FE_DGQ(const unsigned int p);
 
  virtual std::string
  get_name() const override;
 
  virtual void
  get_interpolation_matrix(const FiniteElement<dim, spacedim> &source,
                           FullMatrix<double> &matrix) const override;
 
  virtual void
  get_face_interpolation_matrix(const FiniteElement<dim, spacedim> &source,
                                FullMatrix<double>                 &matrix,
                                const unsigned int face_no = 0) const override;
 
  virtual void
  get_subface_interpolation_matrix(
    const FiniteElement<dim, spacedim> &source,
    const unsigned int                  subface,
    FullMatrix<double>                 &matrix,
    const unsigned int                  face_no = 0) const override;
 
  virtual const FullMatrix<double> &
  get_restriction_matrix(
    const unsigned int         child,
    const RefinementCase<dim> &refinement_case =
      RefinementCase<dim>::isotropic_refinement) const override;
 
  virtual const FullMatrix<double> &
  get_prolongation_matrix(
    const unsigned int         child,
    const RefinementCase<dim> &refinement_case =
      RefinementCase<dim>::isotropic_refinement) const override;
 
  virtual std::vector<std::pair<unsigned int, unsigned int>>
  hp_vertex_dof_identities(
    const FiniteElement<dim, spacedim> &fe_other) const override;
 
  virtual std::vector<std::pair<unsigned int, unsigned int>>
  hp_line_dof_identities(
    const FiniteElement<dim, spacedim> &fe_other) const override;
 
  virtual std::vector<std::pair<unsigned int, unsigned int>>
  hp_quad_dof_identities(const FiniteElement<dim, spacedim> &fe_other,
                         const unsigned int face_no = 0) const override;
 
  virtual bool
  hp_constraints_are_implemented() const override;
 
  virtual FiniteElementDomination::Domination
  compare_for_domination(const FiniteElement<dim, spacedim> &fe_other,
                         const unsigned int codim = 0) const override final;
 
  virtual bool
  has_support_on_face(const unsigned int shape_index,
                      const unsigned int face_index) const override;
 
  virtual std::pair<Table<2, bool>, std::vector<unsigned int>>
  get_constant_modes() const override;
 
  virtual void
  convert_generalized_support_point_values_to_dof_values(
    const std::vector<Vector<double>> &support_point_values,
    std::vector<double>               &nodal_values) const override;
 
  virtual std::unique_ptr<FiniteElement<dim, spacedim>>
  clone() const override;
 
protected:
  FE_DGQ(const std::vector<Polynomials::Polynomial<double>> &polynomials);
 
private:
  static std::vector<unsigned int>
  get_dpo_vector(const unsigned int degree);
 
  void
  rotate_indices(std::vector<unsigned int> &indices,
                 const char                 direction) const;
 
  mutable Threads::Mutex restriction_matrix_mutex;
  mutable Threads::Mutex prolongation_matrix_mutex;
 
  // Allow access from other dimensions.
  template <int dim1, int spacedim1>
  friend class FE_DGQ;
 
  // Allow @p MappingQ class to access to build_renumbering function.
  template <int dim1, int spacedim1>
  friend class MappingQ;
};
 
 
 
template <int dim, int spacedim = dim>
class FE_DGQArbitraryNodes : public FE_DGQ<dim, spacedim>
{
public:
  FE_DGQArbitraryNodes(const Quadrature<1> &points);
 
  virtual std::string
  get_name() const override;
 
  virtual void
  convert_generalized_support_point_values_to_dof_values(
    const std::vector<Vector<double>> &support_point_values,
    std::vector<double>               &nodal_values) const override;
  virtual std::unique_ptr<FiniteElement<dim, spacedim>>
  clone() const override;
};
 
 
 
template <int dim, int spacedim = dim>
class FE_DGQLegendre : public FE_DGQ<dim, spacedim>
{
public:
  FE_DGQLegendre(const unsigned int degree);
 
  virtual std::pair<Table<2, bool>, std::vector<unsigned int>>
  get_constant_modes() const override;
 
  virtual std::string
  get_name() const override;
 
  virtual std::unique_ptr<FiniteElement<dim, spacedim>>
  clone() const override;
};
 
 
 
template <int dim, int spacedim = dim>
class FE_DGQHermite : public FE_DGQ<dim, spacedim>
{
public:
  FE_DGQHermite(const unsigned int degree);
 
  virtual std::string
  get_name() const override;
 
  virtual std::unique_ptr<FiniteElement<dim, spacedim>>
  clone() const override;
};
 
 
DEAL_II_NAMESPACE_CLOSE
 
#endif